Thin silver filaments, copper alloy filaments or gold filaments have been developed for use as connecting wires to coil windings of audio appliances, connecting wires for semiconductor devices, fuse elements, welding materials and also a decoration materials. The metallic filaments are conventionally manufactured using a plurality of processes such as melting, casting, a hot processing and cold wire drawing process which includes a surface cutting, a surface preparation and a thermal processing.
A large amount of production loss tends to occur in the conventional production of wires because of the large number of processing steps as mentioned above. Losses include, for example, sample loss. The production cost of manufacturing thin wires, particularly silver or silver alloy wires, must be very expensive because of the production losses. Also, the yields from the conventional methods are low because of the large number of processes. Moreover, the conventional method requires large and complicated equipment.
In order to improve such defects of the conventional method of the production of the wire, there is proposed a method of making a round wire by releasing a fine jet flow of molten metal into liquid. However, the jet flow of molten silver or silver alloy is unstable, the proposed method has not yet been embodied in the production of thin round metal filament.